internal/pkg: in-flight error resolution

The DCE is a slow and overcomplicated solution to a simple problem. This change replaces the DCE by resolving errors in-flight.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/mbf/main.go

@@ -1196,6 +1196,10 @@ func main() {
 		if w, ok := err.(interface{ Unwrap() []error }); !ok {
 			log.Fatal(err)
 		} else {
+			if _, ok = w.(pkg.InputError); ok {
+				log.Fatal(w)
+			}
+
 			errs := w.Unwrap()
 			for i, e := range errs {
 				if i == len(errs)-1 {